WWDC 2016 starts June 13, according to Siri - CNET

Following its standard playbook, expect Apple at the event to unveil the first official details on its next generation of operating systems for the full range of its hardware empire -- most notably iOS 10 for iPhones and iPads and the successor to the current El Capitan version of OS X for Macs. We may also hear about new features and improvements coming to WatchOS, the software behind the Apple Watch.

While the event remains targeted at app developers and software partners, the opening keynote from CEO Tim Cook is sometimes used as a launchpad for new Apple products and services, such as the big unveiling of Apple Music at last year's event. But with the iPhone SE and new iPad Pro having just been launched, don't be surprised if minor Mac refreshes are the only new items Apple shows off at the event -- if, indeed, there's any new hardware on display at all. (The presumed iPhone 7 is expected to hit in September, as is a potential Apple Watch sequel, if Apple follows its standard release schedule.)

Tickets always sell out in minutes, so potential attendees should be on guard.